Cementation \Cem`en*ta"tion\, n. 1. The act or process of cementing. 2. (Chem.) A process which consists in surrounding a solid body with the powder of other substances, and heating the whole to a degree not sufficient to cause fusion, the physical properties of the body being changed by chemical combination with powder; thus iron becomes steel by cementation with charcoal, and green glass becomes porcelain by cementation with sand.